I had my H1B visa stamping done at Mumbai which had the issue date as 24Apr 2017 and expiration date as 04 Sep 2019
However I did not travel to the US on this visa. Can i now still use this H1B visa to work in the US through another employer ? How can I do so ?
Visa is a travel document and you need a valid visa to enter the US.
To be able to get the visa renewed, you need a valid H1B petition. As your petition has expired, your H1B sponsoring employer will need to file a new petition and once approved you will need to get the visa stamped before you are able to travel to the US and start working for the H1B employer.